transform UI questions

[Casper Boemann]

Hi

Working on my transform tool (yes , I've not given up yet) I have a UI
question:

the order of typical work is:

- select
- choose transform tool
- drag/rotate/whatever
- drag/rotate/whatever
- drag/rotate/whatever
- drag/rotate/whatever
- choosing another tool

Now in photoshop you commit your transform by choosing another tool, and
answering yes to a question dialog. And only then is the action added to the
history buffer.

I was thinking of not putting up a dialog (cannot add new strings anyway),
but to just do the transform. If the user regrets, then undo is always an
option. Doesn't that sound ok?

The originally selected area is cleared as it is transformed to another
place. But when doing successive transforms (as in the example above,
perfecting the transform like the user wants) the intermediate areas
shouldn't be cleared, right?

Now if those intermediate steps are not final steps, should they be added to
the undo history? It would be kind of cool being able to undo the
intermediate steps, but the fact that they are not true steps, makes it a
difficult task to implement (that shouldn't hold us back though).

The implementation problem lies in the fact that I would like to take the
originally selected area as source for every successive transform, thus
avoiding iterative rounding errors.

best regards / venlig hilsen
Casper Boemann